Friedrich hermann hahle



NlTE STATES FRIEDRICH HERMANN HAHLE, OF DRESDEN, GERMANY, ASSIGN OR TO DR. F. VON HEYDEN NAOHFOLGER, OF RADEBEUL, GERMANY.

CATECHOL ETH ER.

' SPECIFICATION forming part of Letters Patent No. 580,57 5, dated April 13, 1897.

Application filed March 7, 1895. Serial No. 540,865. (Specimens) To all whom it may concern:

Be it known that I, FRIEDRICH HERMANN HAHLE, of Dresden, in the Kingdom of Saxony, in the German Empire, have invented a new Alkyl Ether of Pyrocatechin, of which the following is a specification.

This invention consists in a new and hitherto unknown substance, monoethyl ether of pyrocatechin or catechol, which has the chem- Io ical formula This new substance crystallizes with remarkable ease into large Well -developed glassbright colorless prisms which easily melt. The point of setting or solidification of the molten substance is at 26 to 27 centigrade. The substance boils at 215 centigrade. It is very difficultly soluble in water, easily soluble in alcohol and ether and in an aqueous diluted soda-lye, in which the soda salt ONa at 0 U i-I This supposition, however, has proved to be an error. The substance described by Heinisch is not the monoethyl ether of the pyrocatechin. The Heinisch substance is totally different from the monoethyl ether of pyrocatechin. Heinischs substance is a non-crystallizableliquid. The monoethyl ether of the pyrocatechin, however, is a solid substance, characterized by a very extended faculty or ability of crystallization. The Heinisch substance boils at 240 to 241 centigrade. The monoethyl ether of pyrocatechiu, however, boils at 215 centigrade.

The monoethyl ether of the pyrocatechin may be produced in different ways. The simplest manner will be by the ethyliz ation of pyrocatechin, for instance, according to the following statement:

Eleven kilograms of pyrocatechin are dis solved in four kilograms of caustic soda and twenty kilograms of water, and to this solution another solution is added consisting of fourteen and eight-tenths (14.8) kilograms of ethyl sulfate of sodium and sixteen kilograms of water. After thoroughly shaking this mixture the same is digested for about four hours at a pressure of about two to three atmos- 7o pheres. Afterward the contents of the vessel are distilled off by means of steam, whereby the mono and di ethyl ether of pyrooatechin will distil off as colorless oils. Thismixture of the two said ethyl ethers of pyrocatechin is afterward Well mixed with a solution of four kilograms of caustic soda in about twenty-five kilograms of water, and after a certain period of rest the diethyl ether of pyrocatechin, which has remained undissolved, is drawn off and the monoethyl ether of pyrocatechin is separated from the alkaline solution by an acid.

Instead of the 14.8 kilograms of ethyl sulfate of sodium 10.9 kilograms of bromethyl or 6.45 kilograms of chlorethyl may be used.

What 'I claim as my invention is- The within-desoribed new substance, monoethyl ether of pyrocatechin, of the chemical formula OH G I-L OO H and having the following characteristic quali- 5 ties, viz: difficultly soluble in water, easily soluble in alcohol, in ether and in diluted aqueous soda-lye, solidifying with concentrated soda-lye into White salt ON a which on addition of Water Will liquefy, having an aromatic, feebly-thymol-like smell,

to having a boiling-point of 215? centigrade, and

solidifying at from 26 to 27 centigrade, and crystallizing easily into colorless, bright, transparent prisms.

In testimony that I claim the foregoing as my invention I have signed my name in pres- 15 ence of two subscribing witnesses.

FRIEDRICH HERMANN HKHLE.

Witnesses:

HERNANDO DE 80%, WILHELM WIEsENHi'TTTER. 

